diff --git a/tests/asl/test_asl_ref_derive.c b/tests/asl/test_asl_ref_derive.c
index b0c559c..b43e96e 100644
--- a/tests/asl/test_asl_ref_derive.c
+++ b/tests/asl/test_asl_ref_derive.c
@@ -1,4 +1,5 @@
 #include "amduat/asl/ref_derive.h"
+#include "amduat/enc/asl1_core.h"
 #include "amduat/enc/asl1_core_codec.h"
 #include "amduat/hash/asl1.h"